A bill requiring the release of intelligence materials on potential links between the outbreak of the Covid-19 pandemic and a laboratory in the Chinese city of Wuhan has been signed into law by US president Joe Biden.

“We need to get to the bottom of Covid-19’s origins … including potential links to the Wuhan Institute of Virology,” Biden said in a statement.

Biden said that in 2021, after taking office, he had “directed the intelligence community to use every tool at its disposal” to investigate the origins of the virus.

That work is “ongoing,” but as much as possible will be released without causing “harm to national security”, he said.

The bill poses political risks for Biden, who is negotiating a difficult relationship with Chinese leader Xi Jinping.

However, much of Congress wants to pursue the theory further, and the issue has become a rallying point in particular for Biden’s Republican opponents.